Treating complex ores or their concentrates.



WILLIAM MORLEY MARTIN,

OF REDRUTH, ENGLAND.

TREATING COMPLEX ORES 0R THEIR CONCENTRATES.

No Drawing. Original application filed April 15, 1910, Serial No. 555,632.

Specification of Letters Patent.

Patented July 8, 1913 Divided and this application filed September 1, 1910. Serial No. 580,059.

To all whmn v' '15 may concern.

Ile it known that l, \Vnnmxn Monnnr iVlAli'llN, a subject oi? the 'King of Great .llritain, residing at 'lrcwirgie road, lled rut-h, in the county of Cornwall, l lugland, analytical chemist, have invented certain new and useful 1mprovcments in .lrcating Complex ()rcs or Their Concentrates, olf which the :tollmving is a specification.

In my application for United States Letters Patent No. 5%L5520 dated 23rd February 1010, and also in my application, Serial No. 555,632, of which the present applicalion is a division, I have described a process o't treating complex ores consisting in rendering them more amenable to concentration aml to the separation of their constituent minerals by that form of water concentra tion which depends on separation by water owing to the dill'erences in size and speoitic gravity of the particles, which process of treating consists in mixing the si'ibdivided ore or a. concentrate thereof with a solution of an oxidizing agent adapted partially to oxidize the ore at a raised temperature, heating the mass and subjecting the mass to any process of water concentration as above defined. it was explained in that specification that by the term concentratimi processes I do not include leaching or processes Which operate thereby. it was also explained that the action of the oxidizing agentis not known to .me, since although oxidation may occur, it is uncertain whether this oxidation is the muse of the result or whether it is a mere accident to the actual cause.

My present invention, which a division of my application. for United States Il ielters Patent Serial No. 5550 2 dated 15th April. 1910, relates to a treatment oil? complex ores or concentrates thereol by mixing. such ore or concentrates in a subdivided state with a solid oxidizing agent and heating the mass to a temperature at about a dull red heat.

The best oxidizing agents for mixing with the subdivided ore are nitrates. The proportion of the oxidizing agent to be used varies with the nature of the ore or conccntrale to be treated, but generally speaking the smaller the proportion o'l. gangue in an ore the larger must be the proportion ol the oxidizing agent, so a concentrate re quires a more liberal quantity of the agent than the crude ore. On the other hand, when one of the valuable constituents of the ore is in a very line state o'l division, the quantity of the agent may be smaller than when all the constituents are less finely divided. In any case the proportion is coniparatively small, about two per cent. ot the weight of the ore generally sullicing or a crude ore.

I have :lound that in the case of many ores, especially those containing sullids of lead and zinc together with iron pyritcs, it the mass which has been heated with the oxidizing agent, is subjected to a limited oxidizing roasting operation, the iron pyrltes, in so tar as it may not have been already oxidized. may be oxidized first; the mass may then be subjected to water concentration as above defined to separate the oxid of iron from the sullids of lead and zinc and the said sullids may again be subjcctcd to a limited oxidizing roasting in order to oxidize the zinc sullid. A second concentration will now separate the zinc oxid and sulfate (it any) from the lead sullid. In some cases the limited roasting may be carried :l'ar enough to oxidize both the pyritcs and the zinc sullid, a single con centration then serving to separate the lead sullid, separation of the iron and zinc oxids being otherwise ellected. The possibility of e'll'ccting such a dill'ercntial calcination or roasting arises from the preliminary treatment with an oxidizing agent.

As examples of the process the :l'k)ll(i\\'i11g may be given 1. A complex sullid ore containing lead and zinc is suitably subdivided and mixed with l per cent. oi? its weight of solid sodium nitrate. The mixture is heated to dull red, and is then cooled and concentrated by a *alcr concentration process as above dolined.

A complex sullid orc containing lead and zinc together with iron pyriles is suitably subdivided and treated with sodium nitrate in the manner described in Example 1. The mass is then subjected to a limited roasting operation by heating it in a turnace ot the kind usually used for roasting, to which furnace the supply of air is limited. The iron pyrilcs will be oxidized rapidly and the process is easily stopped at this stage. The cooled roasted ore is then coin-.cntratcd by a water (amccntralion process as above dclinod to separate the oxidized pyritcs from the other molalliilcrous mincrals, whereupon the treatment with sodium nitrate is repeated and the mass is again subjected to a limited roasting operation to oxidize the lead sulfate, and finally concentrated.

Having thus described my said invention and the best means I know of carrying the same into practical effect, I claim 1. A process of treating complex ores containing sulfide of lead and zinc, or concentrates thereof, so as to recover the valuable constituents in a separated condition, which process consists in mixing the subdivided material with a solid oxidizing agent in pro portion insuflicient to desulsfurize the ore, then heating the mass comprising the ore and the said agent, and then subjecting the mass to a concentration process to separate a constituent.

2. A process of treating colnplex ores containing sulfids of lead and zinc, or concen- 'then heating the mass comprising the ore and the agent, then sub ecting the mass to a di-fi erential calclnatio-n or roasting, concentrating to separate a constituent, and then successively repeating the operations of calcining and concentrating to separate other constltuents.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

WILLIAM MORLEY MARTIN.

Witnesses:

JAMES WEOKELL, STANLEY VECKELL.

Gopiesof this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

